Hot corrosion behavior of V2O5-coated Gd2Zr2O7 ceramic in air at 700–850 °C

Gd2Zr2O7 ceramic was prepared by solid state reaction at 1650 °C for 10 h in air, and exhibited a defect fluorite-type structure. Reaction between molten V2O5 and Gd2Zr2O7 ceramic was investigated at temperatures ranging from 700 to 850 °C using an X-ray diffractometer (XRD) and scanning electron microscopy (SEM). Molten V2O5 reacted with Gd2Zr2O7 to form ZrV2O7 and GdVO4 at 700 °C; however, in a temperature range of 750–850 °C, molten V2O5 reacted with Gd2Zr2O7 to form GdVO4 and m-ZrO2. Two different reactions observed at 700 °C and 750–850 °C could be explained based on the thermal instability of ZrV2O7.